security: Add transformation sink/source
Change-Id: I2698f79f639c2bd7c3ce2e00f48be634dc4c983d
Refs: #3009
diff --git a/src/security/transform/bool-sink.hpp b/src/security/transform/bool-sink.hpp
new file mode 100644
index 0000000..12e62c9
--- /dev/null
+++ b/src/security/transform/bool-sink.hpp
@@ -0,0 +1,73 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#ifndef NDN_CXX_SECURITY_TRANSFORM_BOOL_SINK_HPP
+#define NDN_CXX_SECURITY_TRANSFORM_BOOL_SINK_HPP
+
+#include "transform-base.hpp"
+
+namespace ndn {
+namespace security {
+namespace transform {
+
+/**
+ * @brief A sink which outputs only one boolean value.
+ *
+ * It checks the first byte that is ever written into the sink,
+ * and set output true if the byte is non-zero, otherwise false.
+ */
+class BoolSink : public Sink
+{
+public:
+ /**
+ * @brief Create a bool sink whose output will be stored in @p value.
+ */
+ explicit
+ BoolSink(bool& value);
+
+private:
+ /**
+ * @brief Check the first byte that is ever received and set the boolean variable.
+ *
+ * @return the same value as @p size.
+ */
+ virtual size_t
+ doWrite(const uint8_t* buf, size_t size) final;
+
+ /**
+ * @brief Finalize sink processing
+ */
+ virtual void
+ doEnd() final;
+
+private:
+ bool m_hasValue;
+ bool& m_value;
+};
+
+unique_ptr<Sink>
+boolSink(bool& value);
+
+} // namespace transform
+} // namespace security
+} // namespace ndn
+
+#endif // NDN_CXX_SECURITY_TRANSFORM_BOOL_SINK_HPP